1. Field of the Invention
This invention relates generally to optical readers, and more particularly to readers capable of reading documents of the type that have markable areas located thereon wherein each of the markable areas contains a plurality of markable locations that may be selectively marked by a writing instrument. Examples of such documents are cards of the type used in state lotteries wherein the player selects certain numbers in a lottery by marking locations on the card corresponding to his choice of lottery numbers. Examples of machines for reading such cards are lottery ticket terminals that have OMR readers (optical mark sense readers) that read such cards and issue tickets bearing the corresponding lottery numbers.
2. Description of the Prior Art
Readers for reading manually marked cards are known. Among such readers are readers generally known as optical mark sense (OMR) readers that have a plurality of sensors disposed within a reading station. The card is passed through the reading station and the presence of a mark is detected as it passes beneath the sensor. Examples of such readers are disclosed in U.S. Pat. Nos. 4,108,361 and 4,032,946.
Other systems scan the card to be read with a video camera or a line scanner to obtain a pattern of light and dark areas, and process this pattern to identify the data on the card. Examples of such systems are disclosed in U.S. Pat. Nos. 3,059,112, 3,246,126, 3,289,172, 3,786,234 and 4,471,217.
While the aforementioned readers do provide a way to read manually markable cards, the OMR type of reader suffers from the disadvantage that the markable locations must be very closely registered with the physical edges of the card, thus requiring highly accurate and costly printing and cutting operations. Also such readers require mechanical transporting mechanisms with close tolerances that are expensive to manufacture and maintain. Another disadvantage of OMRs is that they require some skill on the part of the operator and time to orient the card properly.
Time can be critical in lottery applications where, for example, in the case of popular lottery games the level of sales is often dependent on the efficiency of the agent and terminal in accepting lottery tickets.
The prior art optical scanning types of devices tend also to be complex, expensive, error prone and are subject to similar operator limitations.